picket line

[jatay3]

I believe we are told that it is Imperial strategy to use lines of scouts as pickets and keep the main force back.
How would that work given that the invading fleet likly has not much smaller jump than the pickets?
First all picket ships would have to be J6 to get to the xboat base from which the alarm is sent in time.
second the invaders speed would have to be limited by factors that aren't visible at first glance.
for instance:
the "fleet train"(service ships)could be said to limit the speed of the fleet to the slowest ship. This by the way raises an interesting wrinkle-a commander could make a dash ahead by leaving his fleet train behind-or could pretend to-or could use his fleet train in an unorthodox manner-or whatever. Something simmilar is done in "Norris' gamble" SM11.
Also it takes between two to four hours to refuel a ship from a gas giant: how long a whole fleet-even though some refuel at the same time.
Also it could be decreed that ships jumping or coming out of jump near each other have potential for misjumps major and minor. Thus unless a fleet is extremely well drilled it will enter a given system scattered and will have to reform. Even a well-trained fleet might have to wait for ideal conditions. As a by the way instead of using the normal "jump universe" model I use a sort of "jump particals"-part of the captain's and navigator's job is to find the right combination of jump particals. Also a jump leaves a disturbance in jumpspace which can be detected with the right equipment-and the more tonnage that is jumping from a given place and time(a fleet more than a single ship), and the more jump energy expended(a J2 more than a J1, the more disturbance. This gives a picket more to do.
Moreover large fleets are restricted in their axis of advance not only by the need of finding gas giants but sometimes by the necessity of being able to rendeuvous with supply convoys coming from the base.
All this explains why the picket system would be a hindrance to a major invasion.
What about a raid?
The conclusion I would have to reach is that the pickets have very little chance of stopping a large raid while it is inbound. However if the alarm goes out soon enough the raiders might be prevented from escaping.
Of course there are other permutations. An invader might prepare for a campaign by slowly building up supplie cache(s) at some obscure place. Then at the proper momment several task forces would strike. Each task force would be small enough that it would be assumed to be a raid or a deep patrol,but they could meet at the supply cache and form as a fleet cabable of large operations. Alternativly they could have the help of a dissaffected vassal-both Impies and Zhos must spend a great deal of time trying to destabilize each other.
Thus the strategy of pickets. How are they organized. Perhaps in groups of five or six J6 ships-or however is the minimum necessary to conduct a reasonable search of a system in a reasonable time(tricky math involved in avoiding both leaving systems unsearched and leaving all systems inadequately searched. When an invading force is spotted some would jump out to give a warning while others would delay. In some situations-Vargr corsairs-a picket would go to the nearest naval base of any kind, even of a political rival of it's own state. For instance Confederation Patrol ships might in some circumstances go to a n Impie-even BWA base, or IISS ships go to a Swordie or even Zho base to spread the alarm if the threat is a mutual enemy as with the corsairs.
Does anyone have anything to add?

 

[jatay3]

For instance Confederation Patrol ships might in some circumstances go to a n Impie-even BWA base, or IISS ships go to a Swordie or even Zho base to spread the alarm if the threat is a mutual enemy as with the corsairs.
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the "even" implies my guess as to the attitude. For instance Impies probably regard Zho's as the primary enemy and Swordies as a secondary one. Likewise I think IISS and Confederation Patrol personal would have few hard feelings toward each other and would respect each whereas SWC's would have more animosity toward BDA's-sometimes the animosity would be personal as well as political for there would be torn families and friendships when citizens of the Border worlds are forced to choose between homeworld and confederation.
The picket lines would often overlap and sometimes an IISS picket and a Patrol picket would be in the same star system. As long as both seem to be behaving normally they would leave each other alone and might likly even exchange gossip over the comms.
On some planets there might be places where personal from both sides meet regularly-say a Brubecks on Arden. Or in an Altikregarnir lodge.
There could be other traditions involved with the pickets. One might be that the Patrol sends a greeting to IISS Mora every Emperor's birthday and IISS sends a greeting to Patrol Base Gram every Yule. That of course is not directly related to the picket lines but is a tradition that grew out of centuries of watching one another.
Another possibility is that when they meet in the same system they give a ritualized exchange of insults for each others respective employers.

 

[jatay3]

One possibility is that vargr corsairs at least travel at a slower pace then one might think unless they have a specific target. Rather then hitting and running they ravage an area and move on, trusting in their strength to give them a brief time to do this before the avenger arrives-time a single pirate ship lacks.
Thus pickets smell out the signs. Ships full of refugees, unusual disturbance in traffic, etc is reported when the captain of the picket feels it worth reporting. In return the one with the authority to send the alarm, examines the reports and decides. It is a tough decision. No one wants to be the boy who cries wolf-or the officer who cries "Vargr". But they even less want to fail to pull the alarm when it is needed.